Shall we get the obligatory question about David Beckham out of the way early?

Not that it feels banal or gratuitous to pose it to Adam Moffat. The Houston Dynamo's bearded piranha is tasked with snapping the Beckham supply line, stopping him from finding team-mates with the kind of precise passes that could help win Saturday's MLS Cup final for the Los Angeles Galaxy.

How Moffat plays could define how Beckham exits MLS, as suitors from around the planet watch and wonder how effective the former England captain is at the age of 37. Will there be a Hollywood ending, a dazzling display and a trophy to hoist as the credits roll?

Or will the former England captain be muffled by a Glaswegian who played with limited success for Ross County and Elgin City in the murky depths of the Scottish league, leaving the assembled international media to discuss such unromantic concepts as replica-shirt sales, improved franchise values and bigger television deals while a team of orange-clad relative-unknowns cavort around an emptying Home Depot Center with the silverware.

Asked how he plans to frustrate Beckham, Moffat sighed deeply.

"I don't know. Probably mess his hair up," he said. "He's just a quality player, he's smart, he goes to those spots where he can get in space and whip the ball in. He likes to drop off, get guys to lay it back and look for that ball in. So I think it's being switched on to where he is at all times. He's probably not going to do hundreds of miles of running but he's still a smart player and given time on the ball he can find anyone."

"LA were the better team. I felt like we gave everything we had, it wasn't one of those games where I felt, 'We should have done this, we should have done that,'" Moffat said. "This year there's that bit more hunger, especially with them winning last year, that they're not going to do it twice against us. And I think we were a little bit overwhelmed in that final last year, we never really got going. Now guys are buzzing, getting ready for it, it should be a really good game."

The 2012 model Dynamo are better equipped to beat LA, not least because Moffat has formed a forceful partnership in midfield with Ricardo Clark, the former's hustle complementing the latter's savvy.

"He busts up plays, he gets involved in tackles, he's a good link between the defense and midfield, on the odd occasion he scores spectacular goals," Dominic Kinnear, the Houston head coach, said of Moffat. "I think he brings that little bit of steel in midfield that you need to be a successful team, I really do."

When Beckham's decision to leave Real Madrid for Los Angeles was revealed in January 2007, Moffat was playing in the Scottish third division for Elgin City, some 65 miles northwest of Aberdeen, earning a couple of hundred pounds a week and pondering a career change.

"It wasn't really what I envisaged as a youngster. I was at Ross County for three or four years and never really got into the first team there and for about six or seven months I was kind of at that point where I was like, is this really worth my time?" he said. "I was 20 and hadn't played many first-team games so it kind of looked bleak. I was thinking about college, university, something else. I'd spoken to someone about sports science, physical therapy. Something in the sports field."

A coach he knew mentioned that a new third-tier club in Cleveland, Ohio, was looking for players. They were managed by a Scot: Martin Rennie, who is now in charge of the Vancouver Whitecaps. Moffat knew little about Cleveland other than that LeBron James played basketball there. But he decided to come over for a couple of months and treat the experience like extended pre-season training, expecting to improve his fitness then look for a new club back home.

Instead, he was spotted by Sigi Schmid, who is now the Seattle Sounders' head coach but was then in charge of the Columbus Crew. Signed up by Schmid, Moffat then married the Californian sister of a Crew-mate, Steven Lenhart and one speculative summer in the US turned into what looks like forever.

Taken from Columbus to Portland in 2011 by another Scottish manager, John Spencer, Moffat was hobbled by injuries and spent only 100 minutes on the pitch for the Timbers, over four matches. He had time enough to bring out Thierry Henry's passive aggressive side, though, producing one of the more bizarre red cards for violent conduct that you will ever see.

Moffat was almost subterranean on Portland's depth chart but Kinnear – who was born in Scotland, naturally – traded for him and he became a Dynamo regular, his energy and humility fitting snugly with the team's philosophy.

The 'Moffat rocket'

Smart and amusing off the pitch and uncomplicated on it, the 26-year-old holding midfielder occasionally goes above and beyond his duties, with stunning results. His goal against Sporting Kansas City this month, in the first leg of the Eastern Conference semi-finals, was this week named "play of the year" at the club's annual awards. A long-distance "Moffat rocket" from last year, against Portland, was even better.

Not that he has yet made his fortune. Beckham earned $4m in guaranteed compensation from the Galaxy this year, according to figures from the MLS players' union. Moffat's salary with the Dynamo was recorded as $59,535, though he recently agreed a new contract.

America has not made him rich, but it has given him the scope to realise his potential. "I felt like I'd got a second chance," he said. A lot of people don't get that.

"I was grateful to get that opportunity and I decided I'd give it everything I'd got, really enjoy every moment and savour it. I felt like I got my love for the game back.

"The game over here, I could see it was getting better and the Scottish league's kind of heading in the opposite direction, which is sad. You see the amount of boys who have come over in the last few years. They do enjoy it. They enjoy the lifestyle. I've got a few friends back home I've spoken to who are intrigued by it."

That sounds like a trend that deserves a tag-line. The Moffat effect, perhaps?

"Obviously I was the one that started it all," he deadpanned. "But then Beckham came over..."